The invention provides a method and system for obtaining a three-dimensional representation of a patient's teeth arrangement. A three-dimensional physical teeth model is provided, having a surface relief corresponding to the patient's teeth arrangement. Computerized tomography (CT) is applied to the three-dimensional physical teeth model, to thereby acquire data of multiple slices of at least a portion of the teeth model. The data is analyzed to produce a virtual three-dimensional representation of the teeth model or a portion thereof.